* iseq.h (rb_compile_option_struct): trace instruction is removed so that
  remove the trace_instruction compile option.
  Don't show warning (just ignore) for Ruby 2.5.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61450 b2dd03c8-39d4-4d8f-98ff-823fe69b080e